chapter 3 - RiuNet
chapter 3 - RiuNet
chapter 3 - RiuNet
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GENERAL INTRODUCTION<br />
3. Sperm quality in fish<br />
From an aquacultural point of view, breeding in captivity of some marine<br />
species is a key factor in reaching reproductive success, and the main<br />
limitations are the quantity and quality of male and female gametes.<br />
However, until recently gamete quality has not received much attention,<br />
and only a few studies have been published about the effect of specific<br />
factors on gamete quality (see review Bobe and Labbé, 2000). Traditionally,<br />
hatcheries have focused more on the quality of eggs and larvae rather than<br />
that of sperm, even though sperm quality also affects the performance of<br />
larvae production (Trippel and Nielson, 1992). In fact, sperm in commercial<br />
hatcheries is often inadequate both in terms of quantity and quality and<br />
often optimal fertilisation rates are not reached through in vitro fertilization<br />
trials (Rurangwa et al., 2004). Therefore, it appears that the assessment of<br />
sperm quality would be a useful tool that could be applied in a wide range<br />
of reproduction fields, and several factors such as artificial fertilization,<br />
chilled storage, cryopreservation or even the effect of environmental<br />
pollutants on fish reproductive success could be improved by sperm quality<br />
evaluation (Cabrita et al., 2005a; Fabroccini et al., 2010).<br />
First of all, it seems essential to define and understand what sperm quality<br />
means. From a biological standpoint, sperm quality could be defined as the<br />
ability ofthe spermatozoa to reach and fertilize the oocyte (Fauvel et al.,<br />
2010). In this respect, any quantifiable parameter directly correlated with<br />
the fertilization capacity could potentially be used as a sperm quality<br />
indicator. Sperm is the final result of a maturation process in which several<br />
haploid cells are produced with the aim of transmitting paternal genetic<br />
information to the next generation. It is important to highlight that<br />
throughout this process, several factors can affect the sperm quality and<br />
thus, fertilization success. The most important factors are displayed in Table<br />
1, all of different origins, from the reproductive age of the breeder to the<br />
hormonal treatment (if required) applied to achieve artificial maturation.<br />
Therefore, in order to achieve good quality sperm it is essential to take all<br />
these factors into account, because slight variations in any of them could<br />
negatively affect the sperm quality and thus, decrease fertilization success.<br />
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